Materials may be heated according to various techniques and for various purposes. By way of example, material may be heated as part of a heat-treating operation, a joining operation, or still another operation. Joining two materials involves heating at least one of the materials or heating an intermediate material. Soldering, brazing, and welding often utilize such intermediate materials, which are heated and subsequently cooled, to couple (e.g., physically attach, electrically join, etc.) the two materials. By way of example, solder is utilized to electrically couple leads or contacts of electronic components with contacts of a circuit board to form a circuit assembly. Circuit assemblies often include a plurality of chips or other electronic components each having a plurality of leads or contacts that are soldered to the circuit board.
Traditional methods for soldering the leads or contacts of electronic components to circuit boards include general heating, vapor condensation, and wave soldering. General heating involves placing the electronic components and solder onto the circuit board and inserting the assembly into an oven. The temperature of the oven is increased until the solder melts and couples the electronic components to the circuit board. This process exposes the entire assembly to the heat of the oven, which may damage heat-sensitive constituents (e.g., electronic components, the circuit board, etc.). Vapor condensation involves introducing a vapor into a chamber that contains the solder, electronic components, and circuit board. The solder is melted as the vapor condenses, which transfers energy into the solder equal to the heat of vaporization. However, temperature control of the vapor may prove difficult, and the vapor may itself pose environmental concerns. Nonetheless, general heating, vapor condensation, and wave soldering remain the primary methods used to couple electronic components to circuit boards.